Re: Rotary Spark Gap.

From: 	Joshua Resnick[SMTP:seraphim-at-WPI.EDU]
Sent: 	Wednesday, December 03, 1997 1:14 PM
To: 	Tesla List
Subject: 	Re: Rotary Spark Gap.


> It should be noted here, that non-syncronous RSGs are not recommended
> for
> neon/obit powered coils.  Since you have a non-syncronous motor, you
> should really save this until you get into higher power projects.
> Neon
> sign transformer powered coils have been shown to work well and safely
> with syncronous gaps, which use motors that are synced to the AC line
> frequency at either 1800 ot 3600 rpm.  The syncronous motor, once
> adjusted to the right phase, makes sure that there is always a chance
> for
> a spark when the voltage on the cap is at maximum, saving your cap and
> trannies.
> Brass bolts or bullet nuts (like cap nuts) are often employed for
> electrodes.  Also, Plexiglas is not an acceptable disc material since
> the
> electrodes will melt it and fly off the disk at extreme speeds.  An
> electrode in a 3000 rpm 1ft diameter disc will launch itself with a
> linear velocity of 100 MPH- dangerous!!!  Safe coilers use 1/2" G10
> Fiberglass board for their rotary discs, and polycarbonate shielding
> (1/2" Lexan, which I've seen stop a .45 slug) around the disc.

Thanks for the plexiglass tip!
My transformers are not neons,  they are series rated at 10kv -at- 300MA.